This B vitamin helps prevent malformation of the fetal neural tube, the precursor to the brain and spine. Since 1998, when the FDA mandated folate fortification in breads, cereal and pasta, neural tube defects have plummeted 30 percent in the United States, sparing thousands of babies from spina bifida (abnormal spinal cord development) and anencephaly (impeded brain development). A daily dose of folic acid during the first trimester of pregnancy has been found to reduce neural tube defects by at least 50 percent. Adequate intake prior to pregnancy and during the second trimester can also significantly lower the risk of preterm delivery as well. Doctors recommend increasing folic acid before pregnancy, because brain and spinal cord defects typically develop during the first weeks of gestation, often before a woman knows that she’s pregnant. In fact, a 1991 study published in the Lancet found that supplementation with folic acid beginning around the time of conception reduced the likelihood of having a baby with a neural tube defect in women who were at high risk for this abnormality (due to a previous affected pregnancy).
The importance of folic acid underscores the dangers of low-carb diets, given that such regimens eliminate foods that are fortified with folic acid. Scientists worry that the declining consumption of folate-rich foods could have grave consequences for the next generation. Top whole food folate sources include spinach, asparagus, collard greens, broccoli, turnip greens, Brussels sprouts and beets.
